火遍全球的欢乐、冒险、轻口味吸血鬼系列电影在众人的翘首以盼中迎来了第三部。备受宠爱的吸血鬼姐妹花回来啦！这次她们将迎来家庭新成员：弟弟弗朗兹，又一个有望萌翻全世界的半人吸血鬼宝宝。可从他的出生起，危险和威胁就时刻紧逼。邪恶的吸血鬼女王一心想抢夺她们的心爱的弟弟作为佣仆。席尔瓦尼亚在学校发生了小插曲，失控的魔法眼睛点燃了男同学的衣服和老师的屁股，老师非常生气，而为了安全他们在学校不能公布自己是半人...

Jessica knows exactly what her life is supposed to look like and where it takes her. But then she meets Danny. He has a complicated past and could confuse all their plans. Jessica has to decide....